It's a gear with black outlines on a white background. There are eight squared points on the gear with two circles on the inside that make a hole for other fittings.
This is a Engineering icon. We've made it in iOS style
, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 13,300 icons, all in the same style and quality.